Vaporizer



Sept. 16, 1969 w. E. PFEIFFER VAPORIZER 2 sheets-Sheqt 1 Filed Oct. 18,196'? INVENTOR WILLIAM E. PFElFFER ATTORNEYS Sept. 16, 1969 w. E.PFEIFFER 3,

VAPORIZER Filed Oct. 18, 1967 2 Sheets-Sheet 2 INVENTOR WILLIAM E.PFEIFFER ATTORNEYS United States Patent O 3,467,480 VAPORIZER William E.Pfeiifer, Indianapolis, Ind., assignor to Farm Fans, Inc., Indianapolis,Ind., a corporation of Indiana Filed Oct. 18, 1967, Ser. No. 676,311Int. Cl. F23d 11/44; F23n 5/02, 1/00 U.S. Cl. 43141 2 Claims ABSTRACT OFTHE DISCLOSURE Means for converting liquid fuel to a vapor to be used ina burner, which means comprises a vaporization chamber disposed toreceive heat from the burner, means for selectively and adjustablypositioning the chamber relative to the burner thereby to control thevaporization of fuel in the chamber, first conduit means for connectingthe chamber to a pressurized fuel source and second conduit means forconnecting the chamber to a burner control means and through the controlmeans to the burner. Preferably, a thermostat is arranged to sense thetemperature of the vapor in the second conduit means and to deenergizethe burner when such temperature reaches a predetermined level. Further,pressure regulating means is disposed in the second conduit meansselectively and adjustably to establish the pressure of the fuelsupplied to the burner.

BACKGROUND OF THE INVENTION Field of the invention-The present inventionrelates to gas-fired heaters, and more particularly to the provision ofmeans for converting liquid fuel to a vapor to be used in the burner ofsuch a heater.

Description of the prior art.Conventionally, heaters arranged to burnfuels such as propane gas are connected to the top of a tank whichcontains the gas under pressure. Thus, the vapor at the top of the tankis fed to the burner. As the vapor is drawn from the tank, the liquid inthe tank absorbs heat to produce more vapor. If the ambient temperatureis lower than, say 40 F., and if the rate of usage of vapor issufficiently great, the tank will freeze and the conversion from liquidto vapor will be halted. Generally, when a tank freezes, a coating ofice will develop on the tank. When such an icing condition exists, theresimply is not enough heat, commonly called the heat of vaporization, tovaporize the liquid propane.

This problem is particularly acute when propane burners are utilized ingrain-drying equipment. Generally, farmers must dry their grain usingsuch equipment during the fall and early winter.-

SUMMARY OF THE INVENTION It is a primary object of the present inventionto provide an improved heater of the type comprising a vapor burner andmeans for controlling the flow of fuel to the burner, wherein theimprovement comprises means for connecting the burner to a pressurizedliquid fuel source. The improved heater of the present invention can beconnected to the lower end of a pressurized propane tank to draw liquidpropane from the tank.

Specifically, the means for connecting the burner to the fuel sourcecomprises a vaporization chamber disposed to receive heat from theburner and means for selectively and adjustably positioning the chamberrelative to the burner. First conduit means are provided for connectingthe chamber to the fuel source and second conduit means are provided forconnecting the chamber to the control means for the burner and throughthe control means to the burner. In the heater of the present invention,the liquid fuel is converted to a vapor in the chamber and the requiredheat of vaporization is provided by the burner. The vapor leaves thechamber and flows to the burner.

An appropriate pressure regulating valve is disposed between the chamberand the burner to regulate the pressure of the vapor supplied to theburner, the vapor pres sure at the input side of such regulating valvebeing sub- I stantially equal to the pressure of the fuel in the fueltank.

Preferably, a thermostat is arranged to sense the temperature of thevapor in the second conduit means, i.e., the temperature of the vaporleaving the chamber and flowing toward the burner, and to operate thecontrol means to deenergize the burner when the temperature of the vaporin the second conduit means reaches a predetermined level.

The improvement of the present invention can be provided as a conversionkit for converting burners presently arranged to accept only vapor, suchas that provided at the top of a pressurized propane tank, so that theburners can utilize liquid fuels, such as liquid propane. I

Another object of the present invention is to provide such an improvedheater comprising means for selectively and adjustably positioning thevaporization chamber relative to the burner, thereby to control thevaporization of the fuel in the chamber.

The above-mentioned and other features and objects of this invention andthe manner of attaining them will become more apparent and the inventionitself will be best understood by reference to the following descriptionof an embodiment of the invention taken in conjunction with theaccompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view,partially cut away, showing the improvement of the present inventionembodied in a conventional grain-drying heater;

FIG. 2 is an elevation view showing means for supporting thevaporization chamber in the heater; and

FIG. 3 is an exploded perspective view of the preferred vaporizationchamber and its mounting means.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,and particularly to FIG. 1, it will be seen that there is illustrated aheater, indicated generally by the reference numeral 10, the heatercomprising a gas burner 12 arranged to direct a flame generally in thedirection of the arrow 14 and a burner control means, indicatedgenerally by the reference numeral 16. A blower, not shown, is mountedin the end 18 of the heater 10 and arranged to direct air in thedirection of the arrow 14.

Conventional spreader vanes 20 are comically arranged about the burner12 as clearly shown in FIG. 1.

The burner 12 is arranged to receive fuel in vapor form. The controlmeans 16 includes conventional electrically-operated valves forcontrolling the flow of vapor to the burner 12, one such valve beingindicated by the reference numeral 22.

The improvement of the present invention comprises a toroidally-shapedchamber 24 which serves as a vaporization chamber, 'i.e., a chamber inwhich liquid fuel is converted to vapor. The chamber 24 is positionedforwardly of the burner 12 to receive heat therefrom.

As clearly seen in FIGS. 1 and 3, a transverse, fluidtight partition 26is provided in the chamber 24. Connected to the chamber 24 on one sideof the partition 26 is a rigid pipe 28 and connected to the chamber 24on the other side of the partition 26 is another rigid pipe 30. Ashut-off valve 32 and a pressure-relief valve 34 are connected to thefree end of the pipe 30 as shown in FIG. 1, the pressure-relief valve 34being disposed between the shut-ofi? valve 32 and the chamber 24. Thepipe 30 and the passages through the shut-off valve 32 andpressure-relief valve 34 comprise conduit means for connecting thechamber 24 to a pressurized fuel source, such as a propane tank. It willbe understood that the chamber 24 is to be connected to the fuel sourceto receive liquid fuel.

The free end of the pipe 28 is connected through an elbow fitting 36 toa pressure-regulating valve 40, the output side of the valve 40 beingconnected through a relatively long tube 42 and fittings, indicatedgenerally V by the reference numeral 44, to the electrically-operatedvalve 22 and through that valve 22 to the burner 12. Thus, the pipe 28,elbow fitting 36, the passage through the regulating valve 40, tube 42and fittings 44 all comprise second conduit means for connecting thechamber 24 to the control means 16 and through the control mean 16 tothe burner 12.

The liquid fuel entering the chamber 24 through the pipe 30 is heatedand converted into a vapor usable in the burner 12. The necessary heatfor converting the liquid to a vapor is provided by the burner 12. Thevapor leaving the chamber 24 flows through the pipe 28 and the elbowfitting 36 to the pressure-regulating valve 40. The pressure of thevapor at the input side of the regulating valve 40 is substantiallyequal to the pressure of the fuel in the fuel source connected to thechamber 24. Generally, the pressure-relief valve should prevent gaspressures from exceeding 300 p.s.i. Also, generally, the regulatingvalve 40 is set to provide vapor to the burner 12 at pressures from to30 p.s.i.

A thermostat 46 is mounted on the tube 42 adjacent th fitings 44 and isconnecting to a high limit thermostat 48 comprising a portion of thecontrol means 16, the thermostat 46 being arranged to sense thetemperature of the vapor in the tube 42 and to operate the control means16 to deenergize the burner 12 when the temperature of the vapor in thetube 42 reaches a predetermined level of, for example, 225 F. That is,if the temperature of the vapor leaving the chamber 24 reaches a levelwhich could cause damage to the components comprising the control means16, the burner 12 will be deenergized.

It is desirable to heat the chamber 24 to a point sufficient to vaporizecompletely the liquid fuel contained therein. If the fuel is not beingsufficiently heated, the pipe 28 and tube 42 will tend to accumulate acoating of ice or frost, thereby indicating that further vaporization istaking place therein. If the pipe 28 and the tube 42 tend to accumulatea coating of ice or frost, the chamber 24 should be moved closer to theburner 12. On the other hand, if the thermostat 46 operates the controlmeans 16 to deenergize the burner 12, the chamber 24 should be movedslightly away from the burner 12.

The two pipes 28 and 30 extend through and are supported by a mountingplate 50 as shown in FIGS. 1 and 3. Specifically, a pair of mountingcollars 52 and 53 is rigidly mounted on the plate 50 to extend generallyperpendicularly therefrom, each collar 52, 53 being aligned with anaperture 54, 55 in the mounting plate 50. The pipe 28 is slidablyreceived in the collar 52 and the pipe 30 is slidably received in thecollar 53. A screw 56 is threaded into each collar 52, 53 (FIG. 3) toengage the pipe 28, 30 extending therethrough. Thus, when the screws 56are loosened, the chamber 24 can be moved in the direction of the pipes28 and 30 to position the chamber 24 transaxially relative to the burner12.

The mounting plate 50 is provided to cover an opening, not shown, in theouter, cylindrical wall 67 of the heater 10, the mounting plate 50 beingfastened to the heater by means of the four screws 58, each of whichextends through an opening 60 in the mounting plate, each opening 60being elongated in a direction generally parallel to the arrow 14. Thus,the mounting plate 50 is adjustably movable in a direction generallyparallel to the arrow 14 which is parallel to the axis of thetoroidallyshaped chamber 24.

In the preferred embodiments of the present invention, a brace rod 62 isarranged to provide additional support for the chamber 24, one end ofthe brace rod 62 being connected to the chamber 24 as indicated at 64and the other end of the brace rod 62 being connected to the wall of theheater 10 as indicated at 66.

The connection 66 is shown clearly in FIG. 2. Referring to FIG. 2, itwill be seen that the brace rod 62, which is threaded as illustrated, issecured to the wall 67 of the heater 10 by means of the illustrated nuts70 and 71, a washer 72 and another mounting plate 73. Specifically, therod 62 extends through an opening 68 in the wall 67 and the nut 70 holdsthe washer 72 against the inside surface of the wall 67 while the nut 71holds the mounting plate 73 against the outside surface of the wall 67.

It can be seen that, by loosening the nuts 70 and 71 and the screws 56securing the pipes 28 and 30 relative to the mounting plate 50, thechamber 24 can be adjustably moved in the direction of the pipes 28 and30. Likewise, by loosening the nuts 70 and 71 and the screws 58, themounting plate 50 can be adjustably moved in the direction of theelongated slots 60. Usually, the axis of the chamber 24 will begenerally coincident with the axis of the heater 12.

The vaporizer of the present invention eliminates the need for extralarge or additional propane gas tanks and eliminates the problem of tankfreeze-up. The vaporizer will permit the use of liquid propane as a fuelsupply for a vapor gas burner.

The chamber 24 is preferably constructed from heavy steel pipingdesigned safely to withstand high operating temperatures and gaspressures. In the illustrative embodiment, the chamber 24 is provided bywelding together a pair of elbows with the partition 26 inserted asshown clearly in FIG. 3, the welds being indicated at 75 and 76. Thepipes 28 and 30 are preferably steel pipes welded to the chamber 24 asindicated at 77 and 78, respectively, in FIG. 3.

While there have been discussed above the principles of this inventionin conjunction with specific apparatus, it is to be clearly understoodthat this description is made by way of example and not as a limitationto the scope of the invention.

What is claimed is:

1. An improved heater of the type comprising a burner arranged to beconnected to a pressurized fuel source and means for controlling theflow of fuel to said burner; wherein the improvement comprises means forconnecting the burner to such fuel source, said connecting meanscomprising means defining a vaporization chamber for such fuel spacedfrom said burner and disposed to receive heat therefrom, first conduitmeans for connecting said chamber to such fuel source, second conduitmeans connecting said chamber to said control means and through saidcontrol means to said burner, means for selectively varying the spacingof said chamber from said burner thereby to control the vaporization ofsuch fuel in said chamber when said burner is energized, and athermostat dominatingsaid control means, said thermostat being arrangedto sense the temperature of the vapor in said second conduit means andto operate said control means to deenergize the burner when thetemperature of said vapor reaches a predetermined high value, saidvarying means being adjusted so that the spacing of said chamber fromsaid burner is such that the temperature of the vapor in said secondconduit means is normally less than said high value.

2. An improved heater as in claim 1 wherein said chamber is toroidallyshaped, said chamber being generally axially aligned with said burnerand spaced forwardly thereof, said chamber having a transverse,fluidtight partition therein, said first conduit means being connectedto said chamber on one side of said partition and said second conduitmeans being connected to said chamher on the opposite side of saidpartition; said varying means comprising a mounting plate through whichportions of said first and second conduit means extend, said chamberbeing supported on such portions, first means for mounting said mountingplate on said heater for selectively adjustable movement in a directiongenerally parallel With the axis of said chamber, a brace rod foradditionally supporting said chamber in said heater, means rigidlyconnecting one end of said brace rod to said chamber, and second meansfor mounting the other end of said brace rod on said heater forselectively adjustable axial movement of said chamber; and furthercomprising pressure regulating means disposed in said second conduitmeans and arranged selectively and adjustably to establish the pressureof the fuel supplied to the burner, the pressure at the input side ofsaid regulating means beinggenerally equal to pressure of such fuelsource, a pressure relief valve disposed in said first conduit means,and a selectively actuable valve disposed in said first conduit meansbetween such fuel source and said pressure relief valve.

References Cited UNITED STATES PATENTS 1,529,255 3/1925 Jones 431-2091,788,148 1/1931 Chadwick et a1. 43141 2,559,729 7/ 1951 Nielsen 431-2l12,693,229 11/1954 Fagan 431-209 2,702,989 3/1955 Pagendarm 43141 X2,940,515 6/1960 Hunter et a1. 43111 3,097,687 7/1963 Fannin 43 l41FREDERICK L. MATTESON, Primary Examiner R. A. DUA, Assistant ExaminerUS. Cl. X.R. 431209

